1. Field of the Invention
This invention relates to a food conveying resin belt which can convey bare food.
2. Description of the Related Art
In food conveying resin belts to be used as conveyer belts for conveying food in food manufacturing plants and the like, microorganisms are apt to grow on the belt surface due to adhered residues of food as the material to be conveyed, so that there is a possible danger of spoiling quality and shelf life of food caused by the microorganisms. Accordingly, belts are washed after completion of operations in food manufacturing plants, but, in order to effect complete sterilization of microorganisms, it is necessary to carry out the washing for a prolonged period of time using a drug ..such as sodium hypochlorite, hydrogen peroxide and the like in a high concentration, so that it requires much work to carry out sanitation management.
In consequence, food conveying resin belts containing antibacterial and antifungal agents in their resin layers have been provided in recent years. However, in order to convey food naked, it is necessary to pass the food sanitation law (in Japan: the extraction test of FDA #177-2600, Notification No. 20 by the Ministry of Health and Welfare), so that it is important to use drugs which have low toxicity and high safety as the antibacterial and antifungal agents to be included in the resin layers.
In this connection, antibacterial and antifungal agents can be classified into drugs of inorganic system and organic system. As the former drugs of inorganic system, silver base antibacterial and antifungal agents are widely used, but these drugs have a disadvantage of causing discoloration of resins when kneaded with the resins. Accordingly, their amounts to be added are limited and sufficient antibacterial and antifungal properties therefore cannot be obtained. In addition, with regard to the antifungal effect, these silver based antibacterial and antifungal agents have a problem in that they are not always effective against a broad range of fungi.
On the other hand, the latter drugs of organic system have advantages in that they are relatively low in toxicity and high in safety, because they are effective with small amounts to be added, and also cause less discoloration of resins. Therefore, drugs of organic system are drawing attention as antibacterial and antifungal agents, and 2-(4-thiazolyl)benzimidazole and the like imidazole compounds are particularly used in food conveying resin belts as can be seen in Unexamined Japanese Patent Publication (Kokai) No. Hei. 4-333405 and Unexamined Japanese Patent Publication (Kokai) No. Hei. 4-33406.
However, these imidazole compounds can show certain degree of antifungal effect but almost no antibacterial effect. Accordingly, sufficient antibacterial and antifungal properties can not be added simultaneously to a food conveying resin belt which contains the 2-(4-thiazolyl)benzimidazole or the like imidazole compound in its resin layer.